1. Field of the Invention
The field of the present invention is structural members made of titanium or titanium alloy.
2. Description of the Prior Art
There are conventionally known structural members of this type in which a portion thereof requiring slide characteristic is formed of a .beta.-type titanium alloy having a single .beta.-phase metal structure (see Japanese Patent Application Laid-open No. 247806/86).
However, although the above .beta.-type titanium alloy has a slightly improved slide characteristic as compared with an .alpha.-type and an .alpha.+.beta.-type titanium alloy, it cannot meet the slide characteristic required by a structural member which is used at a high speed and a high surface pressure.